body{
    background-color: #f5f5f5;
    position: relative;
}
.header p{
    line-height: 30px;
    border-bottom: solid 1px rgb(216, 215, 215);
}
.nine{
    position: absolute;
    left: 20%;
    top: 10px;
}
.main .nav_left {
    width: 80%;
    /* height: 100px; */
    position: absolute;
    left: 20%;
    top: 180px;
    text-align: center;
    list-style: none;
}
.main .nav_left a{
    background-color:#66a0de ;
    color: #f5f5f5;
    margin-top: 30px;
}
.nav_left{
    position: absolute;
    top: 50px;
}

 /* .homeworkNews{
    position:absolute;
    width: 50%;
    height:500px;
    margin-left: 25%;
    margin-top: 5%;
      display: block;  
    border: 2px solid black;
    background-color:rgba(170, 214, 87, 0.767);
} */
/* .homeworkNewsTop{
    text-align: center;
    font-size: 30px;
    color: rgb(53, 85, 155);
}  */
/* .homeworkNewsBack{
    width: 20px;
    height: 20px;
    color:aliceblue;
    background-color: red;
    position: absolute;
    right: 0;
    top: 0;
    text-align: center;
}  */


 /* .homeworkNewsCenter td,.homeworkNewsCenter th{
    text-align: center;
    padding-left: 75px;
    padding-right: 75px;
    padding-top: 10px;
}  */


/* .title{
    text-align: center;
    font-size: 30px;
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    font-weight: 700;
} */

 /* .navigation{
    float: left;
    width: 15%;
    height: auto;
    margin-left: 5%;
    margin-top: 3%;
} */

.navigation_ul li .list-group-item{
    display: block;
    width:150px;
    margin-top: 50px;
}

#lookHomework{
    display: block;
}

.submitHomework{
    display: none;
}

/* .studentSubmitBox{
    position:absolute;
    width: 30%;
    height: auto;
    border: 1px solid black;
    background-color: brown;
    margin: 50px 0% 0% 25%;
    z-index: 2;
    display: none;
}

.studentSubmitBoxBack{
    margin-left: 98%;
    width: 10px;
  background-color: red;
  color: aliceblue;
} */

